typedef boost::shared_ptr<A> APtr; void* callbk1 (void* o) { APtr a = *static_cast(o); // or APtr& a = *static_cast(o) a->hello(); } void* callbk1 (void* o) { A* a = static_cast(o); a->hello(); } boost::shared_ptr<A> sPtr(rawPtr); if before a->hello(), the *rawPtr is not destroy(sPtr may be out of scope, but at least one boost::shared_ptr<A> holds it). Use: callbk1(&sPtr); or callbk2(sPtr.get()); If sPtr will out of the scope and no other boost::shared_ptr<A> holds *rawPtr, you should new a boost::shared_ptr<A>: boost::shared_ptr<A>*p = new boost::shared_ptr<A> (sPtr); // keep A life. // pass p to callback callbk3(p); // may be invoke in other thread void callbk3(void* o) { // delete the p = new APtr(sPtr) when return if we only call callbk3 once. boost::scoped_ptr<Aptr> pp(static_cast(o)); APtr& a = *pp; // at least we have this one boost::shared_ptr<A> a->hello(); } Best Regards! Qiao Zhi Qiang

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Message: 6 Date: Tue, 10 May 2011 14:24:26 +0530 (IST) From: Mupparthy Ravindranath To: "boost-users@lists.boost.org" Subject: Re: [Boost-users] How to cast a boost::shared_ptr to void* Message-ID: <443447.3562.qm@web94809.mail.in2.yahoo.com> Content-Type: text/plain; charset="iso-8859-1"

Sorry for the spam.? I got the answer, how to do it. Ignore my previous mail.

[quote] #include #include <iostream> using namespace std;

class A { ??? public: ??? void hello () { cout << "Hello, friends...!" << endl; } };

typedef boost::shared_ptr<A> APtr;

void* callbk (void* o) { ??? APtr a = *static_cast(o); ??? a->hello(); }

int main() { A* rawPtr = new A; boost::shared_ptr<A>sPtr(rawPtr); callbk((void*)&sPtr); return 0; } [/quote]

warm regars, RV